I saw this on the online weathernetwork site.....someone's blog suggested knitting two rows of a scarf, matching the colors of the sky each day. So, for a blue sky with white clouds, you'd hold a blue and a white yarn together, knit a row (or two?). Depending upon time of day too.....if you want to try some sunset colors.
Here's the link:
It does sound like fun. I think I"d want to do a lap blanket instead of a scarf, because I don't like scarves knit in all garter stitch.....too scratchy.